1. Field of Invention
This invention relates to the field of manually operated hand sanders, in particular, the sanding/finishing of car, boat, and truck bodies.
2. Description of Prior Art
A prior art patent search was conducted and a list of patents which appeared to be most pertinent to the invention follows:
U.S. Pat. No. 4,320,601 Haney, Mar. 23, 1982, shows a manual operable sanding block through which a means for delivering water to the work surface is provided. Specifically, the wet sander comprises a block of a size and shape to be comfortably held in a person""s hand. It is rectangular in shape, including two end walls, two sidewalls, the gripping portion including an upper surface, and the base as the lower surface. Pins are embedded in the gripping portion beneath each of the two flaps, that penetrate and retain the ends of the sandpaper which extends across the bottom of the base. A fluid conduit (tube) extends through the side wall of the base and exits through the end wall of the base, forming an L-shaped path through the base, delivering fluid to the work surface in front of the sanding block. An additional feature is a valve positioned in the L-shaped tube allowing the flow of fluid (or water) to be controlled. The disadvantages of this invention are that the movement of the sander is limited to forward and backwards movement because the water is sprayed out of the front of the sander. Also, since there is a valve on the top of the sander to control the water pressure, the valve itself causes an obstruction for the user, and the pressure coming into the sander will be high, leaving the hose rigid and hard to maneuver. The hose or tubing coming into the side of the sander will be awkward and the spikes used to hold the abrasive paper in place can be dangerous and make it difficult to safely remove and insert the paper.
U.S. Pat. No. 5,512,010 Labad, Jr. Apr. 30, 1996, shows a manual wet sanding block having means for supplying liquid from an external source through the sanding block onto the work surface. Specifically, the sanding block comprises a hollow, rigid base, generally shaped in parallelpiped form designed for the ergonomic comfort of the hand of the user, comprising a top, a flat bottom, a right side, a left side, a hollow interior and two spring clamps. A flexible hose connected to the rigid base allows water to flow into the hollow interior of the base and out through holes to a resilient surface located under the flat bottom of the base. The resilient bottom has eight perforations that allow liquid to flow through to the sandpaper or abrasive surface. The sandpaper is supported by the resilient surface and is held in place by two spring clamps, one on each extremity of the rigid base. An additional feature of this wet sanding block is a rubber flexible wiper located on a left side of the rigid base serving to wipe the surface during the sanding process. This sanding block is large and heavy because the interior reservoir must be filled with water for optimum performance. The tube leading to the sander has a restricted flow orifice which controls the water flow to the reservoir. Consequently, it takes a long time to fill. It seems that when using this sander in the vertical position, it would be difficult for the water to be evenly distributed if the water pressure was anything but high. If the water pressure is high, then the hose leading to the conduit would be rigid and more difficult to maneuver. Otherwise the reservoir wouldn""t remain filled and water could not get to the upper holes. The wiper blade adds weight and throws the balance of the sander off. The wiper blade also makes that side of the sander useless for sanding corners etc. There are many moving parts on this sander, some of which are metal which make them more likely to fail or wear (rust, etc).
U.S. Pat. No. 4,922,665 shows a manually operated wet sander comprising a body through which water is supplied to the sanding surface. The wet sander has a contoured handle. The body is constructed from a solid piece of rubber, or other suitable material. A thin cushion of durable material is attached to the bottom of the body. Sand paper is wrapped around the thin cushion and held in place by grooves which are located on opposite sides of the sander. An inlet for introduction of a liquid from an external source is provided at the top surface of the sander. An adapter is used to connect a hose between an external liquid source and the inlet. Liquid flows from the inlet through a conduit and out through a plurality of outlets in the bottom body of the sander and out along the edges of the sandpaper onto the work surface. An additional embodiment is shown where the front of the sander has jaws (grooves) to hold the front end of the sandpaper in place and a roll of sandpaper is attached to the back of the sander, providing a continuous supply of fresh sandpaper. This sander is heavier and bulkier to use and has moving parts (springs and levers, etc.) which are more likely to fail.
U.S. Pat. No. 2,765,593 Salmon et al. teaches a manual sanding block for dry sanding only, that is essentially rectangular with a rounded gripping portion. The ends of the block are horizontally bisected by slits which extend to the interior of the block. The surfaces of the slits have complementary recesses, ridges, to hold the ends of the abrasive paper in place. One end of the sanding block is square, while the other end is rounded. The abrasive paper folds over the lower rounded edge and is held in the slit. While this rounded end will be useful for large concave surfaces, it will not be usable in areas with small radiuses of curvature, such as door jambs. Also, because of the design of the block and the size of the curved edge, the user""s hand will come in contact with the abrasive paper during use, causing potential discomfort.
An objective of the invention is to provide a manually operated universal sanding block that is lightweight, inexpensive, and can be used in the wet mode or dry mode equally well.
A further objective of this invention is to provide a manually operated sanding block which during wet operation provides a sufficient and evenly distributed flow of fluid, such as water, to the work surface when attached to a higher pressure external valved source of fluid, such as a garden hose, without the need for incorporating an independent mechanical valve or regulator.
A further objective of this invention is to provide a manually operated sanding block in which the abrasive material can be easily and safely loaded and unloaded without harm to the user, the sanding block, or the paper.
A further objective of this invention is to provide a manually operated sanding block that can be used horizontally, vertically, and for narrow, hard to reach spaces, such as door jambs or areas with a small radius of curvature.
A further objective of this invention is to provide a manually operated sanding block that has no metal/moving parts that will wear of fail with time and use.
Other objectives of the invention will become readily apparent to those skilled in the art from the following description and the accompanying drawings.